The B-1 port unfortunately didn't give me back any codes. So when you say take off the controller, you want me to remove the ECC (as in the whole control panel?) & look for soot & charred components? Sorry, I'm not very car savvy.

I guess it would be an electronic unit then. It has temperature settings for both the driver & passenger, & fan speed is controlled by a sliding bar.

I have a '94 Volvo 850 turbo, & I can't adjust or turn off the heater. It was in the off position, & all of a sudden it comes on full blast & a bit of smoke came out of the vents. It only turns off when I turn off the vehicle, & it won't allow me to adjust the settings. Any help?